Kinetis Bootloader 1.1.0 Reference Manual - NXP … · 2016-11-23 · Kinetis Bootloader 1.1.0 Reference Manual, Rev. 0, ... 46 5.11 ReceiveSBFile ... Clean up the IAR project

Kinetis Bootloader 1.1.0 ReferenceManual

Rev 0, 12/2014

Kinetis Bootloader 1.1.0 Reference Manual, Rev. 0, 12/2014

2 Freescale Semiconductor, Inc.

Contents

Section number Title Page

Chapter 1Introduction

1.1 Introduction.....................................................................................................................................................................7

1.2 Terminology....................................................................................................................................................................7

1.3 Block diagram.................................................................................................................................................................8

1.4 Features supported.......................................................................................................................................................... 8

1.5 Components supported....................................................................................................................................................9

Chapter 2Functional description

2.1 Introduction.....................................................................................................................................................................11

2.2 Memory map...................................................................................................................................................................11

2.3 The Kinetis Bootloader Configuration Area (BCA).......................................................................................................11

2.4 Start-up process...............................................................................................................................................................13

2.5 Clock configuration........................................................................................................................................................ 14

2.6 Bootloader entry point.................................................................................................................................................... 15

Chapter 3Kinetis bootloader protocol

3.1 Introduction.....................................................................................................................................................................17

3.2 Command with no data phase.........................................................................................................................................17

3.3 Command with incoming data phase..............................................................................................................................18

3.4 Command with outgoing data phase...............................................................................................................................19

Chapter 4Bootloader packet types

4.1 Introduction.....................................................................................................................................................................23

4.2 Ping packet......................................................................................................................................................................23

4.3 Ping response packet.......................................................................................................................................................24

4.4 Framing packet................................................................................................................................................................25

4.5 CRC16 algorithm............................................................................................................................................................27


Freescale Semiconductor, Inc. 3


4.6 Command packet............................................................................................................................................................ 28

4.7 Response packet..............................................................................................................................................................29

Chapter 5Kinetis bootloader command API

5.1 Introduction.....................................................................................................................................................................33

5.2 GetProperty command.................................................................................................................................................... 33

5.3 SetProperty command.....................................................................................................................................................35

5.4 FlashEraseAll command................................................................................................................................................. 37

5.5 FlashEraseRegion command...........................................................................................................................................38

5.6 FlashEraseAllUnsecure command.................................................................................................................................. 39

5.7 ReadMemory command..................................................................................................................................................40

5.8 WriteMemory command.................................................................................................................................................42

5.9 FillMemory command.................................................................................................................................................... 44

5.10 FlashSecurityDisable command......................................................................................................................................46

5.11 ReceiveSBFile command................................................................................................................................................47

5.12 Execute command...........................................................................................................................................................47

5.13 Call command................................................................................................................................................................. 48

5.14 Reset command...............................................................................................................................................................48

5.15 FlashProgramOnce command.........................................................................................................................................49

5.16 FlashReadOnce command.............................................................................................................................................. 51

5.17 FlashReadResource command........................................................................................................................................ 52

Chapter 6Supported peripherals

6.1 Introduction.....................................................................................................................................................................55

6.2 I2C Peripheral................................................................................................................................................................. 55

6.3 SPI Peripheral................................................................................................................................................................. 57

6.4 UART Peripheral............................................................................................................................................................ 59

6.5 USB Peripheral............................................................................................................................................................... 61

6.5.1 Clock configuration..............................................................................................................................................62




6.5.2 Device descriptor................................................................................................................................................. 62

6.5.3 Endpoints............................................................................................................................................................. 64

6.5.4 HID reports.......................................................................................................................................................... 64

Chapter 7Peripheral interfaces

7.1 Introduction.....................................................................................................................................................................67

7.2 Abstract control interface................................................................................................................................................68

7.3 Abstract byte interface.................................................................................................................................................... 69

7.4 Abstract packet interface.................................................................................................................................................70

7.5 Framing packetizer..........................................................................................................................................................70

7.6 USB HID packetizer....................................................................................................................................................... 70

7.7 Command/data processor................................................................................................................................................71

Chapter 8Memory interface

8.1 Abstract interface............................................................................................................................................................ 73

8.2 Flash driver interface...................................................................................................................................................... 74

8.3 Low level flash driver..................................................................................................................................................... 74

Chapter 9Kinetis bootloader porting

9.1 Introduction.....................................................................................................................................................................77

9.2 Choosing a starting point................................................................................................................................................ 77

9.3 Preliminary porting tasks................................................................................................................................................ 77

9.3.1 Download device header files.............................................................................................................................. 78

9.3.2 Copy the closest match........................................................................................................................................ 78

9.3.3 Provide device startup file (vector table)............................................................................................................. 78

9.3.4 Clean up the IAR project..................................................................................................................................... 79

9.3.5 Bootloader peripherals......................................................................................................................................... 80

9.4 Primary porting tasks...................................................................................................................................................... 82

9.4.1 Header file modification...................................................................................................................................... 82




9.4.2 Bootloader peripherals......................................................................................................................................... 83

9.4.2.1 Supported peripherals............................................................................................................................ 83

9.4.2.2 Peripheral initialization.......................................................................................................................... 83

9.4.2.3 Clock initialization.................................................................................................................................84

9.4.3 Bootloader configuration..................................................................................................................................... 84

9.4.4 Bootloader memory map configuration............................................................................................................... 85

Chapter 10Creating a custom flash-resident bootloader

10.1 Introduction.....................................................................................................................................................................87

10.2 Where to start..................................................................................................................................................................87

10.3 Flash-resident bootloader source tree............................................................................................................................. 88

10.4 Modifying source files.................................................................................................................................................... 90

10.5 Example.......................................................................................................................................................................... 90

10.6 Modifying the peripherals_<mcu>.c file........................................................................................................................ 91

10.7 Removing unused files from the project.........................................................................................................................91

Chapter 11Revision history



Chapter 1Introduction

1.1 Introduction

The Kinetis bootloader is a configurable flash programming utility that operates over aserial connection on Kinetis MCUs. It enables quick and easy programming of KinetisMCUs through the entire product life cycle, including application development, finalproduct manufacturing, and beyond. The bootloader is delivered in two ways. TheKinetis bootloader is provided as full source code that is highly configurable. Thebootloader is also preprogrammed by Freescale into ROM or flash on select Kinetisdevices. Host-side command line and GUI tools are available to communicate with thebootloader. Users can utilize host tools to upload/download application code via thebootloader.

1.2 Terminology

target

The device running the bootloader firmware (aka the ROM).

host

The device sending commands to the target for execution.

source

The initiator of a communications sequence. For example, the sender of a command ordata packet.

destination

Receiver of a command or data packet.

incoming



From host to target.

outgoing

From target to host.

1.3 Block diagram

This block diagram describes the overall structure of the Kinetis bootloader.

Figure 1-1. Block diagram

1.4 Features supported

Here are some of the features supported by the Kinetis bootloader:

Block diagram



• Supports UART, I2C, SPI and USB peripheral interfaces.• Automatic detection of the active peripheral.• Ability to disable any peripheral.• UART peripheral implements autobaud.• Common packet-based protocol for all peripherals.• Packet error detection and retransmit.• Flash-resident configuration options.• Fully supports flash security, including ability to mass erase or unlock security via

the backdoor key.• Protection of RAM used by the bootloader while it is running.• Provides command to read properties of the device, such as Flash and RAM size.• Multiple options for executing the bootloader either at system start-up or under

application control at runtime.

1.5 Components supported

Components for the bootloader firmware:

• Startup code (clocking, pinmux, etc.)• Command phase state machine• Command handlers

• GenericResponse• FlashEraseAll• FlashEraseRegion• ReadMemory• ReadMemoryResponse• WriteMemory• FillMemory• FlashSecurityDisable• GetProperty• GetPropertyResponse• ReceiveSBFile• Execute• Call• Reset• SetProperty• FlashEraseAllUnsecure• FlashProgramOnce• FlashReadOnce• FlashReadOnceResponse

Chapter 1 Introduction



• FlashReadResource• FlashReadResourceResponse

• SB file state machine• Packet interface

• Framing packetizer• Command/data packet processor

• Command implementation• Flash erase all• Flash erase region• Read memory• Write memory• Fill memory• Flash security disable• Get property• Recieve SB file• Execute• Call• Reset• Set property• Flash program once• Flash read once• Flash read resource

• Memory interface• Abstract interface• Flash Driver Interface• Low level flash driver

• Peripheral drivers• I2C slave• SPI slave• UART

• Auto-baud detector• USB device HID class

• USB controller driver• USB framework• USB HID class

• CRC check engine• CRC algorithm

Components supported



Chapter 2Functional description

2.1 IntroductionThe following subsections describe the Kinetis bootloader functionality.

2.2 Memory map

See the Kinetis bootloader chapter of the reference manual of your particular SoC for theROM and RAM memory map used by the bootloader.

2.3 The Kinetis Bootloader Configuration Area (BCA)The Kinetis bootloader reads data from the Bootloader Configuration Area (BCA) toconfigure various features of the bootloader. The BCA resides in flash memory at offset0x3C0 from the beginning of the user application, and provides all of the parametersneeded to configure the Kinetis bootloader operation. For uninitialized flash, the Kinetisbootloader uses a predefined default configuration. A host application can use the Kinetisbootloader to program the BCA for use during subsequent initializations of thebootloader.

Table 2-1. Configuration Fields for the Kinetis bootloader

Offset Size (bytes) Configuration Field Description

0x00 - 0x03 4 tag Magic number to verify bootloaderconfiguration is valid. Must be set to'kcfg'.

0x04 - 0x07 4 crcStartAddress Start address for application imageCRC check. To generate the CRC,refer to the CRC chapter.

Table continues on the next page...



Table 2-1. Configuration Fields for the Kinetis bootloader (continued)

Offset Size (bytes) Configuration Field Description

0x08 - 0x0B 4 crcByteCount Byte count for application image CRCcheck.

0x0C - 0x0F 4 crcExpectedValue Expected CRC value for applicationCRC check.

0x10 1 enabledPeripherals Bitfield of peripherals to enable.

bit 0 LPUART

bit 1 I2C

bit 2 SPI

bit 4 USB

0x11 1 i2cSlaveAddress If not 0xFF, used as the 7-bit I2Cslave address.

0x12 - 0x13 2 peripheralDetectionTimeout If not 0xFF, used as the timeout inmilliseconds for active peripheraldetection.

0x14 - 0x15 2 usbVid Sets the USB Vendor ID reported bythe device during enumeration.

0x16- 0x17 2 usbPid Sets the USB Product ID reported bythe device during enumeration.

0x18 - 0x1B 4 usbStringsPointer Sets the USB Strings reported by thedevice during enumeration.

0x1C 1 clockFlags See Table 2-3, clockFlagsConfiguration Field

0x1D 1 clockDivider Divider to use for core and bus clockswhen in high speed mode.

0x1E 1 - Reserved.

0x1F 1 - Reserved.

0x20 4 - Reserved.

0x24 4 - Reserved.

The first configuration field 'tag' is a tag value or magic number. The tag value must beset to 'kcfg' for the bootloader configuration data to be recognized as valid. If tag-fieldverification fails, the Kinetis bootloader acts as if the configuration data is not present.The tag value is treated as a character string, so bytes 0-3 must be set as shown in thetable.

Table 2-2. tag Configuration Field

Offset tag Byte Value

0 'k' (0x6B)

1 'c' (0x63)

2 'f' (0x66)

3 'g' (0x67)

The Kinetis Bootloader Configuration Area (BCA)



The flags in the clockFlags configuration field are enabled if the corresponding bit iscleared (0).

Table 2-3. clockFlags Configuration Field

Bit Flag Description

0 HighSpeed Enable high speed mode (i.e., 48 MHz).

1 - 7 - Reserved.

2.4 Start-up processThese conditions force the hardware to start the Kinetis bootloader:

• The BOOTSRC_SEL field of FOPT register is set to either 0b11 or 0b10. This forcesthe ROM to run out of reset.

• The BOOTCFG0 pin is asserted. The pin must be configured as BOOTCFG0 bysetting the BOOTPIN_OPT bit of FOPT to 0.

• A user applications running on flash or RAM calls into the Kinetis bootloader entrypoint address in ROM, to start Kinetis bootloader execution.

The BOOTSRC_SEL bits (FOPT register, FOPT [7:6]) determine the boot source. TheFOPT register is located in the flash configuration field at address 0x40D in the flashmemory array. For a complete list of options, see the Boot options section in the Resetand Boot chapter of the reference manual for your specific SoC. If BOOTSRC_SEL is setto 0b11 or 0b10, the device boots to ROM out of reset. Flash memory defaults to all 1swhen erased, so a blank chip automatically boots to ROM.

The BOOTCFG0 pin is shared with the NMI pin, with NMI being the default usage.Regardless of whether the NMI pin is enabled or not, the NMI functionality is disabled ifthe ROM is executed out of reset, for as long as the ROM is running.

When the ROM is executed out of reset, vector fetches from the CPU are redirected tothe ROM's vector table in ROM memory at offset 0x0. This ensures that any exceptionsare handled by the ROM.

After the Kinetis bootloader has started, the following procedure starts bootloaderoperations:

1. The RCM_MR [FORCEROM] bits are set so the device reboots back into the ROMif/when the device is reset.

2. Initializes the bootloader's .data and .bss sections.3. Reads bootloader configuration data from flash at offset 0x3C0. The configuration

data is only used if the tag field is set to the expected 'kcfg' value. If the tag is

Chapter 2 Functional description



incorrect, then the configuration values are set to default, as if the data was all 0xFFbytes.

4. Clocks are configured.5. Enabled peripherals are initialized.6. The bootloader waits for communication to begin on a peripheral.

• If detection times out, the bootloader jumps to the user application in flash.• If communication is detected, all inactive peripherals are shut down, and the

command phase is entered.

Figure 2-1. Kinetis bootloader start-up flowchart

2.5 Clock configuration

Clock configuration



By default, the bootloader does not modify clocks. Kinetis bootloader in ROM uses theclock configuration of the chip out of reset, unless the clock configuration bits in theFOPT register are cleared, or if a USB peripheral is enabled.

• Alternate clock configurations are supported by setting fields in the bootloaderconfiguration data.

• If the HighSpeed flag of the clockFlags configuration value is cleared or if a USBperipheral is enabled, the bootloader enables the internal 48 MHz reference clock.Higher speed clocks are used when available.

• In high-speed mode, the core and bus clock frequencies are determined by theclockDivider configuration value.

• The core clock divider is set directly from clockDivider, unless a USB peripheral isenabled. If a USB peripheral is enabled and clockDivider is greater than 2,clockDivider is reduced to 2 in order to keep the CPU clock above 20 MHz.

• The bus clock divider is set to 1, unless the resulting bus clock frequency would begreater than the maximum supported value. In this case, the bus clock divider isincreased until the bus clock frequency is at or below the maximum.

• Note that the maximum baud rate of serial peripherals is related to the core and busclock frequencies. To achieve the desired baud rates, high-speed mode should beenabled in BCA.

2.6 Bootloader entry pointThe Kinetis bootloader provides a function (runBootloader) that a user application cancall, to run the bootloader.

To get the address of the entry point, the user application reads the word containing thepointer to the bootloader API tree at offset 0x1C of the bootloader's vector table. Thevector table is placed at the base of the bootloader's address range, which is0x1C00_0000 for the ROM. Thus, the API tree pointer is at address 0x1C00_001C.

The bootloader API tree is a structure that contains pointers to other structures, whichhave the function and data addresses for the bootloader. The bootloader entry point isalways the first word of the API tree.

The prototype of the entry point is:

void run_bootloader(void * arg);

The arg parameter is currently unused, and intended for future expansion. For example,passing options to the bootloader. To ensure future compatibility, a value of NULLshould be passed for arg.

Example code to get the entry pointer address from the ROM and start the bootloader:

Chapter 2 Functional description



// Variables

uint32_t runBootloaderAddress;

void (*runBootloader)(void * arg);

// Read the function address from the ROM API tree.

runBootloaderAddress = **(uint32_t **)(0x1c00001c);

runBootloader = (void (*)(void * arg))runBootloaderAddress;

// Start the bootloader.

runBootloader(NULL);

NOTEThe user application must be executing at Supervisor(Privileged) level when calling the bootloader entry point.

Bootloader entry point



Chapter 3Kinetis bootloader protocol

3.1 Introduction

This section explains the general protocol for the packet transfers between the host andthe Kinetis bootloader. The description includes the transfer of packets for differenttransactions, such as commands with no data phase and commands with incoming oroutgoing data phase. The next section describes various packet types used in atransaction.

Each command sent from the host is replied to with a response command.

Commands may include an optional data phase.

• If the data phase is incoming (from the host to Kinetis bootloader ), it is part of theoriginal command.

• If the data phase is outgoing (from Kinetis bootloader to host), it is part of theresponse command.

3.2 Command with no data phase

NOTEIn these diagrams, the Ack sent in response to a Command orData packet can arrive at any time before, during, or after theCommand/Data packet has processed.

Command with no data phase

The protocol for a command with no data phase contains:

• Command packet (from host)• Generic response command packet (to host)



Figure 3-1. Command with no data phase

3.3 Command with incoming data phase

The protocol for a command with incoming data phase contains:

• Command packet (from host)(kCommandFlag_HasDataPhase set)• Generic response command packet (to host)• Incoming data packets (from host)• Generic response command packet (to host)

Command with incoming data phase



Figure 3-2. Command with incoming data phase

Notes

• The host may not send any further packets while it is waiting for the response to acommand.

• The data phase is aborted if the Generic Response packet prior to the start of the dataphase does not have a status of kStatus_Success.

• Data phases may be aborted by the receiving side by sending the final GenericResponse early with a status of kStatus_AbortDataPhase. The host may abort thedata phase early by sending a zero-length data packet.

• The final Generic Response packet sent after the data phase includes the status forthe entire operation.

3.4 Command with outgoing data phase

Chapter 3 Kinetis bootloader protocol



The protocol for a command with an outgoing data phase contains:

• Command packet (from host)• ReadMemory Response command packet (to host)(kCommandFlag_HasDataPhase

set)• Outgoing data packets (to host)• Generic response command packet (to host)

Figure 3-3. Command with outgoing data phase

Note

• The data phase is considered part of the response command for the outgoing dataphase sequence.

• The host may not send any further packets while the host is waiting for the responseto a command.

• The data phase is aborted if the ReadMemory Response command packet, prior tothe start of the data phase, does not contain the kCommandFlag_HasDataPhase flag.

Command with outgoing data phase



• Data phases may be aborted by the host sending the final Generic Response earlywith a status of kStatus_AbortDataPhase. The sending side may abort the data phaseearly by sending a zero-length data packet.

• The final Generic Response packet sent after the data phase includes the status forthe entire operation.

Chapter 3 Kinetis bootloader protocol



Command with outgoing data phase



Chapter 4Bootloader packet types

4.1 IntroductionThe Kinetis bootloader device works in slave mode. All data communication is initiatedby a host, which is either a PC or an embedded host. The Kinetis bootloader device is thetarget, which receives a command or data packet. All data communication between hostand target is packetized.

NOTEThe term "target" refers to the "Kinetis bootloader device".

There are 6 types of packets used:• Ping packet• Ping Response packet• Framing packet• Command packet• Data packet• Response packet

All fields in the packets are in little-endian byte order.

4.2 Ping packetThe Ping packet is the first packet sent from a host to the target to establish a connectionon selected peripheral in order to run autobaud. The Ping packet can be sent from host totarget at any time that the target is expecting a command packet. If the selected peripheralis UART, a ping packet must be sent before any other communications. For other serialperipherals it is optional, but is recommended in order to determine the serial protocolversion.

In response to a Ping packet, the target sends a Ping Response packet, discussed in latersections.



Table 4-1. Ping Packet Format

Byte # Value Name

0 0x5A start byte

1 0xA6 ping

Target executes UART autobaud if necessary

Host Target

Ping Packet: 0X5a 0xa6

PingResponse Packet: 0x5a 0xa7 0x00 0x00 0x01 0x50 0x00 0x00 0x29 0xae

Figure 4-1. Ping Packet Protocol Sequence

4.3 Ping response packetThe target sends a Ping Response packet back to the host after receiving a Ping packet. Ifcommunication is over a UART peripheral, the target uses the incoming Ping packet todetermine the baud rate before replying with the Ping Response packet. Once the PingResponse packet is received by the host, the connection is established, and the host startssending commands to the target.

Table 4-2. Ping Response packet format

Byte # Value Parameter

0 0x5A start byte

1 0xA7 Ping response code

2 Protocol bugfix

3 Protocol minor

4 Protocol major

5 Protocol name = 'P' (0x50)

6 Options low

7 Options high


Ping response packet



Table 4-2. Ping Response packet format (continued)


8 CRC16 low

9 CRC16 high

The Ping Response packet can be sent from host to target any time the target expects acommand packet. For the UART peripheral, it must be sent by host when a connection isfirst established, in order to run autobaud. For other serial peripherals it is optional, butrecommended to determine the serial protocol version. The version number is in the sameformat at the bootloader version number returned by the GetProperty command.

4.4 Framing packetThe framing packet is used for flow control and error detection for the communicationslinks that do not have such features built-in. The framing packet structure sits betweenthe link layer and command layer. It wraps command and data packets as well.

Every framing packet containing data sent in one direction results in a synchronizingresponse framing packet in the opposite direction.

The framing packet described in this section is used for serial peripherals including theUART, I2C, and SPI. The USB HID peripheral does not use framing packets. Instead, thepacketization inherent in the USB protocol itself is used.

Table 4-3. Framing Packet Format


0 0x5A start byte

1 packetType

2 length_low Length is a 16-bit field that specifies the entirecommand or data packet size in bytes.3 length_high

4 crc16_low This is a 16-bit field. The CRC16 value covers entireframing packet, including the start byte and commandor data packets, but does not include the CRC bytes.See the CRC16 algorithm after this table.

5 crc16_high

6 . . .n Command or Data packetpayload

CRC16 algorithm:

uint16_t crc16_update(const uint8_t * src, uint32_t lengthInBytes)

{

Chapter 4 Bootloader packet types



uint32_t crc = 0;

uint32_t j;

for (j=0; j < lengthInBytes; ++j)

{

uint32_t i;

uint32_t byte = src[j];

crc ^= byte << 8;

for (i = 0; i < 8; ++i)

{

uint32_t temp = crc << 1;

if (crc & 0x8000)

{

temp ^= 0x1021;

}

crc = temp;

}

}

return crc;

}

A special framing packet that contains only a start byte and a packet type is used forsynchronization between the host and target.

Table 4-4. Special Framing Packet Format


0 0x5A start byte

1 0xAn packetType

The Packet Type field specifies the type of the packet from one of the defined types(below):

Table 4-5. packetType Field

packetType Name Description

0xA1 kFramingPacketType_Ack The previous packet was received successfully; the sendingof more packets is allowed.

0xA2 kFramingPacketType_Nak The previous packet was corrupted and must be re-sent.


Framing packet



Table 4-5. packetType Field (continued)

packetType Name Description

0xA3 kFramingPacketType_AckAbort Data phase is being aborted.

0xA4 kFramingPacketType_Command The framing packet contains a command packet payload.

0xA5 kFramingPacketType_Data The framing packet contains a data packet payload.

0xA6 kFramingPacketType_Ping Sent to verify the other side is alive. Also used for UARTautobaud.

0xA7 kFramingPacketType_PingResponse A response to Ping; contains the framing protocol versionnumber and options.

4.5 CRC16 algorithmThis section provides the CRC16 algorithm.

uint16_t crc16_update(const uint8_t * src, uint32_t lengthInBytes)

{

uint32_t crc = 0;

uint32_t j;

for (j=0; j < lengthInBytes; ++j)

{

uint32_t i;

uint32_t byte = src[j];

crc ^= byte << 8;

for (i = 0; i < 8; ++i)

{

uint32_t temp = crc << 1;

if (crc & 0x8000)

{

temp ^= 0x1021;

}

crc = temp;

}

}

return crc;




}

4.6 Command packetThe command packet carries a 32-bit command header and a list of 32-bit parameters.

Table 4-6. Command Packet Format

Command Packet Format (32 bytes)

Command Header (4 bytes) 28 bytes for Parameters (Max 7 parameters)

Tag Flags Rsvd ParamCount

Param1(32-bit)

Param2(32-bit)

Param3(32-bit)

Param4(32-bit)

Param5(32-bit)

Param6(32-bit)

Param7(32-bit)

byte 0 byte 1 byte 2 byte 3

Table 4-7. Command Header Format

Byte # Command Header Field

0 Command or Response tag The command header is 4 bytes long, withthese fields.1 Flags

2 Reserved. Should be 0x00.

3 ParameterCount

The header is followed by 32-bit parameters up to the value of the ParameterCount fieldspecified in the header. Because a command packet is 32 bytes long, only 7 parameterscan fit into the command packet.

Command packets are also used by the target to send responses back to the host. Asmentioned earlier, command packets and data packets are embedded into framing packetsfor all of the transfers.

Table 4-8. Command Tags

Command Tag Name

0x01 FlashEraseAll The command tag specifies one of thecommands supported by the Kinetisbootloader. The valid command tags for theKinetis bootloader are listed here.

0x01 FlashEraseAll The command tag specifies one of thecommands supported by the Kinetisbootloader. The valid command tags for theKinetis bootloader are listed here.

0x02 FlashEraseRegion

0x03 ReadMemory

0x04 WriteMemory

0x05 FillMemory

0x06 FlashSecurityDisable Reserved

0x07 GetProperty

0x08 ReceiveSbFile

0x09 Execute


Command packet



Table 4-8. Command Tags (continued)

Command Tag Name

0x10 FlashReadResource

0x11 Reserved

0x0A Call

0x0B Reset

0x0C SetProperty

0x0D FlashEraseAllUnsecure

0x0D Reserved

0x0E FlashProgramOnce

0x0F FlashReadOnce

Table 4-9. Response Tags

Response Tag Name

0xA0 GenericResponse The response tag specifies one of the responsesthe Kinetis bootloader (target) returns to the host.The valid response tags are listed here.

0xA0 GenericResponse The response tag specifies one of the responsesthe Kinetis bootloader (target) returns to the host.The valid response tags are listed here.

0xA7 GetPropertyResponse (used for sendingresponses to GetProperty command only)

0xA3 ReadMemoryResponse (used for sendingresponses to ReadMemory command only)

0xAF FlashReadOnceResponse (used for sendingresponses to FlashReadOnce command only)

0xB0 FlashReadResourceResponse (used for sendingresponses to FlashReadResource commandonly)

Flags: Each command packet contains a Flag byte. Only bit 0 of the flag byte is used. Ifbit 0 of the flag byte is set to 1, then data packets follow in the command sequence. Thenumber of bytes that are transferred in the data phase is determined by a command-specific parameter in the parameters array.

ParameterCount: The number of parameters included in the command packet.

Parameters: The parameters are word-length (32 bits). With the default maximumpacket size of 32 bytes, a command packet can contain up to 7 parameters.

4.7 Response packetThe responses are carried using the same command packet format wrapped with framingpacket data. Types of responses include:

• GenericResponse




• GetPropertyResponse• ReadMemoryResponse• FlashReadOnceResponse• FlashReadResourceResponse

GenericResponse: After the Kinetis bootloader has processed a command, thebootloader sends a generic response with status and command tag information to the host.The generic response is the last packet in the command protocol sequence. The genericresponse packet contains the framing packet data and the command packet data (withgeneric response tag = 0xA0) and a list of parameters (defined in the next section). Theparameter count field in the header is always set to 2, for status code and command tagparameters.

Table 4-10. GenericResponse Parameters

Byte # Parameter Descripton

0 - 3 Status code The Status codes are errors encountered during the execution of acommand by the target. If a command succeeds, then a kStatus_Successcode is returned. Table 1, Kinetis BootloaderFlashloader Status ErrorCodes, lists the status codes returned to the host by the Kinetisbootloader.

4 - 7 Command tag The Command tag parameter identifies the response to the command sentby the host.

GetPropertyResponse: The GetPropertyResponse packet is sent by the target inresponse to the host query that uses the GetProperty command. The GetPropertyResponsepacket contains the framing packet data and the command packet data, with thecommand/response tag set to a GetPropertyResponse tag value (0xA7).

The parameter count field in the header is set to greater than 1, to always include thestatus code and one or many property values.

Table 4-11. GetPropertyResponse Parameters


0 - 3 Status code

4 - 7 Property value

. . . . . .

Can be up to maximum 6 property values, limited to the size of the 32-bitcommand packet and property type.

Response packet



ReadMemoryResponse: The ReadMemoryResponse packet is sent by the target inresponse to the host sending a ReadMemory command. The ReadMemoryResponsepacket contains the framing packet data and the command packet data, with thecommand/response tag set to a ReadMemoryResponse tag value (0xA3), the flags fieldset to kCommandFlag_HasDataPhase (1).

The parameter count set to 2 for the status code and the data byte count parameters shownbelow.

Table 4-12. ReadMemoryResponse Parameters

Byte # Parameter Descripton

0 - 3 Status code The status of the associated Read Memory command.

4 - 7 Data byte count The number of bytes sent in the data phase.

FlashReadOnceResponse:The FlashReadOnceResponse packet is sent by the target inresponse to the host sending a FlashReadOnce command. The FlashReadOnceResponsepacket contains the framing packet data and the command packet data, with thecommand/response tag set to a FlashReadOnceResponse tag value (0xAF), and the flagsfield set to 0. The parameter count is set to 2 plus the number of words requested to beread in the FlashReadOnceCommand.

Table 4-13. FlashReadOnceResponse Parameters


0 – 3 Status Code

4 – 7 Byte count to read

… …

Can be up to 20 bytes of requested read data.

The FlashReadResourceResponse packet is sent by the target in response to the hostsending a FlashReadResource command. The FlashReadResourceResponse packetcontains the framing packet data and command packet data, with the command/responsetag set to a FlashReadResourceResponse tag value (0xB0), and the flags field set tokCommandFlag_HasDataPhase (1).

Table 4-14. FlashReadResourceResponse Parameters


0 – 3 Status Code

4 – 7 Data byte count




Response packet



Chapter 5Kinetis bootloader command API

5.1 Introduction

All Kinetis bootloader command APIs follows the command packet format wrapped bythe framing packet as explained in previous sections.

For a list of commands supported by Kinetis bootloader refer to Section 5.

For a list of status codes returned by Kinetis bootloader refer to Appendix A.

5.2 GetProperty commandThe GetProperty command is used to query the bootloader about various properties andsettings. Each supported property has a unique 32-bit tag associated with it. The tagoccupies the first parameter of the command packet. The target returns aGetPropertyResponse packet with the property values for the property identified with thetag in the GetProperty command.

Properties are the defined units of data that can be accessed with the GetProperty orSetProperty commands. Properties may be read-only or read-write. All read-writeproperties are 32-bit integers, so they can easily be carried in a command parameter.

For a list of properties and their associated 32-bit property tags supported by Kinetisbootloader, refer to Appendix B.

The 32-bit property tag is the only parameter required for GetProperty command.

Table 5-1. Parameters for GetProperty Command

Byte # Command

0 - 3 Property tag



Process command

Host Target

GetProperty: Property tag = 0x010x5a a4 08 00 73 d4 07 00 00 01 01 00 00 00

0x5a a4 0c 00 07 7a a7 00 00 02 00 00 00 00 00 00 01 4b

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

Figure 5-1. Protocol Sequence for GetProperty Command

Table 5-2. GetProperty Command Packet Format (Example)

GetProperty Parameter Value

Framing packet start byte 0x5A

packetType 0xA4, kFramingPacketType_Command

length 0x08 0x00

crc16 0x73 0xD4

Command packet commandTag 0x07 – GetProperty

flags 0x00

reserved 0x00

parameterCount 0x01

propertyTag 0x00000001 - CurrentVersion

The GetProperty command has no data phase.

Response: In response to a GetProperty command, the target sends aGetPropertyResponse packet with the response tag set to 0xA7. The parameter countindicates the number of parameters sent for the property values, with the first parametershowing status code 0, followed by the property value(s). The next table shows anexample of a GetPropertyResponse packet.

Table 5-3. GetProperty Response Packet Format (Example)

GetPropertyResponse Parameter Value



length 0x0c 0x00 (12 bytes)


GetProperty command



Table 5-3. GetProperty Response Packet Format (Example) (continued)

GetPropertyResponse Parameter Value

crc16 0x07 0x7a

Command packet responseTag 0xA7

flags 0x00

reserved 0x00

parameterCount 0x02

status 0x00000000

propertyValue 0x0000014b - CurrentVersion

5.3 SetProperty commandThe SetProperty command is used to change or alter the values of the properties oroptions of the bootloader. The command accepts the same property tags used with theGetProperty command. However, only some properties are writable--see Appendix B. Ifan attempt to write a read-only property is made, an error is returned indicating theproperty is read-only and cannot be changed.

The property tag and the new value to set are the two parameters required for theSetProperty command.

Table 5-4. Parameters for SetProperty Command

Byte # Command

0 - 3 Property tag

4 - 7 Property value

Chapter 5 Kinetis bootloader command API



Process command

Host Target

SetProperty: Property tag = 10, Property Value = 10x5a a4 0c 00 67 8d 0c 00 00 02 0a 00 00 00 01 00 00 00

GenericResponse:0x5a a4 00 9e 10 a0 00 0c 02 00 00 00 00 0c 00 00 00

ACK:0x5a a1

ACK:0x5a a1

Figure 5-2. Protocol Sequence for SetProperty Command

Table 5-5. SetProperty Command Packet Format (Example)

SetProperty Parameter Value



length 0x0C 0x00

crc16 0x67 0x8D

Command packet commandTag 0x0C – SetProperty with property tag 10

flags 0x00

reserved 0x00

parameterCount 0x02

propertyTag 0x0000000A - VerifyWrites

propertyValue 0x00000001

The SetProperty command has no data phase.

Response: The target returns a GenericResponse packet with one of following statuscodes:

Table 5-6. SetProperty Response Status Codes

Status Code

kStatus_Success

kStatus_ReadOnly

kStatus_UnknownProperty

kStatus_InvalidArgument

SetProperty command



5.4 FlashEraseAll commandThe FlashEraseAll command performs an erase of the entire flash memory. If any flashregions are protected, then the FlashEraseAll command fails and returns an error statuscode. Executing the FlashEraseAll command releases flash security if it (flash security)was enabled, by setting the FTFA_FSEC register. However, the FSEC field of the flashconfiguration field is erased, so unless it is reprogrammed, the flash security is re-enabledafter the next system reset. The Command tag for FlashEraseAll command is 0x01 set inthe commandTag field of the command packet.

The FlashEraseAll command requires no parameters.

Process command

Host Target

FlashEraseAll0x5a a4 04 00 c4 2e 01 00 00 00

0x5a a4 0c 00 53 63 a0 00 04 02 00 00 00 00 01 00 00 00

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

Figure 5-3. Protocol Sequence for FlashEraseAll Command

Table 5-7. FlashEraseAll Command Packet Format (Example)

FlashEraseAll Parameter Value



length 0x04 0x00

crc16 0xC4 0x2E

Command packet commandTag 0x01 - FlashEraseAll

flags 0x00

reserved 0x00

parameterCount 0x00

The FlashEraseAll command has no data phase.




Response: The target returns a GenericResponse packet with status code either set tokStatus_Success for successful execution of the command, or set to an appropriate errorstatus code.

5.5 FlashEraseRegion commandThe FlashEraseRegion command performs an erase of one or more sectors of the flashmemory.

The start address and number of bytes are the 2 parameters required for theFlashEraseRegion command. The start and byte count parameters must be 4-byte aligned([1:0] = 00), or the FlashEraseRegion command fails and returnskStatus_FlashAlignmentError(101). If the region specified does not fit in the flashmemory space, the FlashEraseRegion command fails and returnskStatus_FlashAddressError(102). If any part of the region specified is protected, theFlashEraseRegion command fails and returns kStatus_MemoryRangeInvalid(10200).

Table 5-8. Parameters for FlashEraseRegion Command

Byte # Parameter

0 - 3 Start address

4 - 7 Byte count

The FlashEraseRegion command has no data phase.

Response: The target returns a GenericResponse packet with one of following errorstatus codes.

Table 5-9. FlashEraseRegion Response Status Codes

Status Code

kStatus_Success (0)

kStatus_MemoryRangeInvalid (10200)

kStatus_FlashAlignmentError (101)

kStatus_FlashAddressError (102)

kStatus_FlashAccessError (103)

kStatus_FlashProtectionViolation (104)

kStatus_FlashCommandFailure (105)

FlashEraseRegion command



5.6 FlashEraseAllUnsecure commandThe FlashEraseAllUnsecure command performs a mass erase of the flash memory,including protected sectors. Flash security is immediately disabled if it (flash security)was enabled, and the FSEC byte in the flash configuration field at address 0x40C isprogrammed to 0xFE. However, if the mass erase enable option in the FSEC field isdisabled, then the FlashEraseAllUnsecure command fails.

The FlashEraseAllUnsecure command requires no parameters.

Process command

Host Target

FlashEraseAllUnsecure0x5a a4 04 00 f6 61 0d 00 cc 00

0x5a a4 0c 00 61 2c a0 00 04 02 00 00 00 00 0d 00 00 00

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

Figure 5-4. Protocol Sequence for FlashEraseAll Command

Table 5-10. FlashEraseAllUnsecure Command Packet Format (Example)

FlashEraseAllUnsecure Parameter Value



length 0x04 0x00

crc16 0xF6 0x61

Command packet commandTag 0x0D - FlashEraseAllUnsecure

flags 0x00

reserved 0x00

parameterCount 0x00

The FlashEraseAllUnsecure command has no data phase.




Response: The target returns a GenericResponse packet with status code either set tokStatus_Success for successful execution of the command, or set to an appropriate errorstatus code.

5.7 ReadMemory commandThe ReadMemory command returns the contents of memory at the given address, for aspecified number of bytes. This command can read any region of memory accessible bythe CPU and not protected by security.

The start address and number of bytes are the two parameters required for ReadMemorycommand.

Table 5-11. Parameters for read memory command

Byte Parameter Description

0-3 Start address Start address of memory to read from

4-7 Byte count Number of bytes to read and return to caller

ReadMemory command



Figure 5-5. Command sequence for read memory

ReadMemory Parameter Value

Framing packet Start byte 0x5A0xA4,

packetType kFramingPacketType_Command

length 0x0C 0x00

crc16 0x1D 0x23

Command packet commandTag 0x03 - readMemory

flags 0x00

reserved 0x00

parameterCount 0x02

startAddress 0x20000400

byteCount 0x00000064

Data Phase: The ReadMemory command has a data phase. Since the target works inslave mode, the host need pull data packets until the number of bytes of data specified inthe byteCount parameter of ReadMemory command are received by host.

Response: The target returns a GenericResponse packet with a status code either set tokStatus_Success upon successful execution of the command, or set to an appropriateerror status code.




5.8 WriteMemory commandThe WriteMemory command writes data provided in the data phase to a specified rangeof bytes in memory (flash or RAM). However, if flash protection is enabled, then writesto protected sectors fail.

Special care must be taken when writing to flash.• First, any flash sector written to must have been previously erased with a

FlashEraseAll, FlashEraseRegion, or FlashEraseAllUnsecure command.• First, any flash sector written to must have been previously erased with a

FlashEraseAll or FlashEraseRegion command.• Writing to flash requires the start address to be 4-byte aligned ([1:0] = 00).• The byte count is rounded up to a multiple of 4, and trailing bytes are filled with the

flash erase pattern (0xff).• If the VerifyWrites property is set to true, then writes to flash also performs a flash

verify program operation.

When writing to RAM, the start address does not need to be aligned, and the data is notpadded.

The start address and number of bytes are the 2 parameters required for WriteMemorycommand.

Table 5-13. Parameters for WriteMemory Command

Byte # Command

0 - 3 Start address

4 - 7 Byte count

WriteMemory command



Process command

Host Target

WriteMemory: startAddress = 0x20000400, byteCount = 0x640x5a a4 0c 00 06 5a 04 00 00 02 00 04 00 20 64 00 00 00

Generic Response:0x5a a4 0c 00 27 1f a0 00 ff 02 00 00 00 00 04 00 00 00

ACK: 0x5a a1

ACK: 0x5a a1

Data packet :0x5a a5 20 00 CRC16 32 bytes data

Process DataACK: 0x5a a1

Final Data packet0x5a a5 length16 CRC16 32 bytes data

ACK

Process Data

Generic Response0x5a a4 0c 00 23 72 a0 00 00 02 00 00 00 00 04 00 00 00

ACK: 0x5a a1

Figure 5-6. Protocol Sequence for WriteMemory Command

Table 5-14. WriteMemory Command Packet Format (Example)

WriteMemory Parameter Value



length 0x0C 0x00

crc16 0x06 0x5A

Command packet commandTag 0x04 - writeMemory

flags 0x00

reserved 0x00

parameterCount 0x02






Data Phase: The WriteMemory command has a data phase; the host sends data packetsuntil the number of bytes of data specified in the byteCount parameter of theWriteMemory command are received by the target.

Response: The target returns a GenericResponse packet with a status code set tokStatus_Success upon successful execution of the command, or to an appropriate errorstatus code.

5.9 FillMemory commandThe FillMemory command fills a range of bytes in memory with a data pattern. It followsthe same rules as the WriteMemory command. The difference between FillMemory andWriteMemory is that a data pattern is included in FillMemory command parameter, andthere is no data phase for the FillMemory command, while WriteMemory does have adata phase.

Table 5-15. Parameters for FillMemory Command

Byte # Command

0 - 3 Start address of memory to fill

4 - 7 Number of bytes to write with the pattern• The start address should be 32-bit aligned.• The number of bytes must be evenly divisible by 4. (Note: for a part that

uses FTFE flash, the start address should be 64-bit aligned, and thenumber of bytes must be evenly divisible by 8).

8 - 11 32-bit pattern

• To fill with a byte pattern (8-bit), the byte must be replicated 4 times in the 32-bitpattern.

• To fill with a short pattern (16-bit), the short value must be replicated 2 times in the32-bit pattern.

For example, to fill a byte value with 0xFE, the word pattern would be 0xFEFEFEFE; tofill a short value 0x5AFE, the word pattern would be 0x5AFE5AFE.

Special care must be taken when writing to flash.• First, any flash sector written to must have been previously erased with a

FlashEraseAll, FlashEraseRegion, or FlashEraseAllUnsecure command.• First, any flash sector written to must have been previously erased with a

FlashEraseAll or FlashEraseRegion command.

FillMemory command



• Writing to flash requires the start address to be 4-byte aligned ([1:0] = 00).• If the VerifyWrites property is set to true, then writes to flash also performs a flash

verify program operation.

When writing to RAM, the start address does not need to be aligned, and the data is notpadded.

Process command

Host Target

FillMemory, with word pattern 0x12345678

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

0x5a a4 10 00 e4 57 05 00 00 03 00 70 00 00 00 08 00 00 78 56 34 12

0x5a a4 0c 00 97 04 a0 00 00 02 00 00 00 00 05 00 00 00

Figure 5-7. Protocol Sequence for FillMemory Command

Table 5-16. FillMemory Command Packet Format (Example)

FillMemory Parameter Value



length 0x10 0x00

crc16 0xE4 0x57

Command packet commandTag 0x05 – FillMemory

flags 0x00

Reserved 0x00

parameterCount 0x03



patternWord 0x12345678

The FillMemory command has no data phase.

Response: upon successful execution of the command, the target (Kinetis Flashloader)returns a GenericResponse packet with a status code set to kStatus_Success, or to anappropriate error status code.




5.10 FlashSecurityDisable commandThe FlashSecurityDisable command performs the flash security disable operation, bycomparing the 8-byte backdoor key (provided in the command) against the backdoor keystored in the flash configuration field (at address 0x400 in the flash).

The backdoor low and high words are the only parameters required forFlashSecurityDisable command.

Table 5-17. Parameters for FlashSecurityDisable Command

Byte # Command

0 - 3 Backdoor key low word

4 - 7 Backdoor key high word

Process command

Host Target

FlashSecureDisable, with backdoor key 01020304050607080x5a a4 0c 00 43 7b 06 00 00 04 03 02 01 08 07 06 05

0x5a a4 0c 00 35 78 a0 00 0c 02 00 00 00 00 06 00 00 00

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

Figure 5-8. Protocol Sequence for FlashSecurityDisable Command

Table 5-18. FlashSecurityDisable Command Packet Format (Example)

FlashSecurityDisable Parameter Value



length 0x0C 0x00

crc16 0x43 0x7B

Command packet commandTag 0x06 - FlashSecurityDisable

flags 0x00

reserved 0x00


FlashSecurityDisable command



Table 5-18. FlashSecurityDisable Command Packet Format (Example) (continued)

FlashSecurityDisable Parameter Value

parameterCount 0x02

Backdoorkey_low 0x04 0x03 0x02 0x01

Backdoorkey_high 0x08 0x07 0x06 0x05

The FlashSecurityDisable command has no data phase.

Response: The target returns a GenericResponse packet with a status code either set tokStatus_Success upon successful execution of the command, or set to an appropriateerror status code.

5.11 ReceiveSBFile commandThe Receive SB File command (ReceiveSbFile) starts the transfer of an SB file to thetarget. The command only specifies the size in bytes of the SB file that is sent in the dataphase. The SB file is processed as it is received by the bootloader.

Table 5-19. Parameters for Receive SB File Command

Byte # Command

0 - 3 Byte count

Data Phase: The Receive SB file command has a data phase; the host sends data packetsuntil the number of bytes of data specified in the byteCount parameter of the Receive SBFile command are received by the target.

Response: The target returns a GenericResponse packet with a status code set to thekStatus_Success upon successful execution of the command, or set to an appropriateerror code.

5.12 Execute commandThe execute command results in the bootloader setting the program counter to the code atthe provided jump address, R0 to the provided argument, and a Stack pointer to theprovided stack pointer address. Prior to the jump, the system is returned to the reset state.

The Jump address, function argument pointer, and stack pointer are the parametersrequired for the Execute command.




Table 5-20. Parameters for Execute Command

Byte # Command

0 - 3 Jump address

4 - 7 Argument word

8 - 11 Stack pointer address

The Execute command has no data phase.

Response: Before executing the Execute command, the target validates the parametersand return a GenericResponse packet with a status code either set to kStatus_Success oran appropriate error status code.

5.13 Call commandThe Call command executes a function that is written in memory at the address sent inthe command. The address needs to be a valid memory location residing in accessibleflash (internal or external) or in RAM. The command supports the passing of one 32-bitargument. Although the command supports a stack address, at this time the call still takesplace using the current stack pointer. After execution of the function, a 32-bit return valueis returned in the generic response message.

Table 5-21. Parameters for Call Command

Byte # Command

0 - 3 Call address

4 - 7 Argument word

8 - 11 Stack pointer

Response: The target returns a GenericResponse packet with a status code either set tothe return value of the function called or set to kStatus_InvalidArgument (105).

5.14 Reset commandThe Reset command results in the bootloader resetting the chip.

The Reset command requires no parameters.

Call command



Process command

Host Target

Reset0x5a a4 04 00 6f 46 0b 00 00 00

GenericResponse:0x5a a4 0c 00 f8 0b a0 00 04 02 00 00 00 00 0b 00 00 00

ACK :0x5a a1

ACK:0x5a a1

Figure 5-9. Protocol Sequence for Reset Command

Table 5-22. Reset Command Packet Format (Example)

Reset Parameter Value



length 0x04 0x00

crc16 0x6F 0x46

Command packet commandTag 0x0B - reset

flags 0x00

reserved 0x00

parameterCount 0x00

The Reset command has no data phase.

Response: The target returns a GenericResponse packet with status code set tokStatus_Success, before resetting the chip.

5.15 FlashProgramOnce commandThe FlashProgramOnce command writes data (that is provided in a command packet) to aspecified range of bytes in the program once field. Special care must be taken whenwriting to the program once field.




• The program once field only supports programming once, so any attempted toreprogram a program once field gets an error response.

• Writing to the program once field requires the byte count to be 4-byte aligned or 8-byte aligned.

The FlashProgramOnce command uses three parameters: index 2, byteCount, data.

Table 5-23. Parameters for FlashProgramOnce Command

Byte # Command

0 - 3 Index of program once field

4 - 7 Byte count (must be evenly divisible by 4)

8 - 11 Data

12 - 16 Data

Process command

Host Target

FlashProgramOnce: index=0, byteCount=4, data=0x12345678

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

0x5a a4 10 00 7e 89 0e 00 00 03 00 00 00 00 04 00 00 00 78 56 34 12

0x5a a4 0c 00 88 1a a0 00 00 02 00 00 00 00 0e 00 00 00

Figure 5-10. Protocol Sequence for FlashProgramOnce Command

Table 5-24. FlashProgramOnce Command Packet Format (Example)

FlashProgramOnce Parameter Value



length 0x10 0x00

crc16 0x7E4 0x89

Command packet commandTag 0x0E – FlashProgramOnce

flags 0

reserved 0

parameterCount 3

index 0x0000_0000


FlashProgramOnce command



Table 5-24. FlashProgramOnce Command Packet Format (Example) (continued)

FlashProgramOnce Parameter Value

byteCount 0x0000_0004

data 0x1234_5678

Response: upon successful execution of the command, the target (Kinetis Flashloader)returns a GenericResponse packet with a status code set to kStatus_Success, or to anappropriate error status code.

5.16 FlashReadOnce commandThe FlashReadOnce command returns the contents of the program once field by givenindex and byte count. The FlashReadOnce command uses 2 parameters: index andbyteCount.

Table 5-25. Parameters for FlashReadOnce Command

Byte # Parameter Description

0 - 3 index Index of the program once field (to read from)

4 - 7 byteCount Number of bytes to read and return to the caller

Process command

Host Target

FlashReadOnce: index=0, byteCount=4

ACK:0x5a a1

ACK:0x5a a1

Generic Response:

0x5a a4 0c 00 c1 a5 0f 00 00 02 00 00 00 00 04 00 00 00

0x5a a4 10 00 3f 6f af 00 00 03 00 00 00 00 04 00 00 00 78 56 34 12

Figure 5-11. Protocol Sequence for FlashReadOnce Command




Table 5-26. FlashReadOnce Command Packet Format (Example)

FlashReadOnce Parameter Value


packetType 0xA4

length 0x0C 0x00

crc 0xC1 0xA5

Command packet commandTag 0x0F – FlashReadOnce

flags 0x00

reserved 0x00

parameterCount 0x02

index 0x0000_0000


Table 5-27. FlashReadOnce Response Format (Example)

FlashReadOnceResponse

Parameter Value


packetType 0xA4

length 0x10 0x00

crc 0x3F 0x6F

Command packet commandTag 0xAF

flags 0x00

reserved 0x00

parameterCount 0x03

status 0x0000_0000


data 0x1234_5678

Response: upon successful execution of the command, the target returns aFlashReadOnceResponse packet with a status code set to kStatus_Success, a byte countand corresponding data read from Program Once Field upon successful execution of thecommand, or returns with a status code set to an appropriate error status code and a bytecount set to 0.

5.17 FlashReadResource commandThe FlashReadResource command returns the contents of the IFR field or Flash firmwareID, by given offset, byte count, and option. The FlashReadResource command uses 3parameters: start address, byteCount, option.

FlashReadResource command



Table 5-28. Parameters for FlashReadResource Command

Byte # Parameter Command

0 - 3 start address Start address of specific non-volatile memory to be read

4 - 7 byteCount Byte count to be read

8 - 11 option 0: IFR

1: Flash firmware ID

Process command

Host Target

ACK: 0x5a a1

ACK: 0x5a a1

Data packet

Process Data

ACK: 0x5a a1

Generic Response

ACK: 0x5a a1

FlashReadResource: start address=0, byteCount=8, option=1

5a a4 10 00 b3 cc 10 00 00 03 00 00 00 00 08 00 00 00 01 00 00 00

FlashReadResource Response5a a4 0c 00 08 d2 b0 01 00 02 00 00 00 00 08 00 00 00

5a a5 08 00 9c d3 00 08 00 00 00 01 00 06

5a a4 0c 00 75 a3 a0 00 00 02 00 00 00 00 10 00 00 00

Figure 5-12. Protocol Sequence for FlashReadResource Command

Table 5-29. FlashReadResource Command Packet Format (Example)

FlashReadResource Parameter Value


packetType 0xA4

length 0x10 0x00

crc 0xB3 0xCC

Command packet commandTag 0x10 – FlashReadResource

flags 0x00





Table 5-29. FlashReadResource Command Packet Format (Example) (continued)

FlashReadResource Parameter Value

reserved 0x00

parameterCount 0x03

startAddress 0x0000_0000


option 0x0000_0001

Table 5-30. FlashReadResource Response Format (Example)

FlashReadResourceResponse

Parameter Value


packetType 0xA4

length 0x0C 0x00

crc 0xD2 0xB0

Command packet commandTag 0xB0

flags 0x01

reserved 0x00

parameterCount 0x02

status 0x0000_0000


Data phase: The FlashReadResource command has a data phase. Because the target(Kinetis bootloader) works in slave mode, the host must pull data packets until thenumber of bytes of data specified in the byteCount parameter of FlashReadResourcecommand are received by the host.

FlashReadResource command



Chapter 6Supported peripherals

6.1 IntroductionThis section describes the peripherals supported by the Kinetis bootloader. To use aninterface for bootloader communications, the peripheral must be enabled in the BCA.Ifthe BCA is invalid (such as all 0xFF bytes), then all peripherals are enabled by default.

6.2 I2C PeripheralThe Kinetis bootloader supports loading data into flash via the I2C peripheral, where theI2C peripheral serves as the I2C slave. A 7-bit slave address is used during the transfer.

Customizing an I2C slave address is also supported. This feature is enabled if theBootloader Configuration Area (BCA) is enabled (tag field is filled with ‘kcfg’) and thei2cSlaveAddress field is filled with a value other than 0xFF. Otherwise, 0x10 is used asthe default I2C slave address.

The Kinetis Flashloader uses 0x10 as the I2C slave address, and supports 400 kbps as theI2C baud rate.

The maximum supported I2C baud rate depends on corresponding clock configurationfield in the BCA. Typical supported baud rate is 400 kbps with factory settings. Actualsupported baud rate may be lower or higher than 400 kbps, depending on the actual valueof the clockFlags and the clockDivider fields.

Because the I2C peripheral serves as an I2C slave device, each transfer should be startedby the host, and each outgoing packet should be fetched by the host.

• An incoming packet is sent by the host with a selected I2C slave address and thedirection bit is set as write.



• An outgoing packet is read by the host with a selected I2C slave address and thedirection bit is set as read.

• 0x00 is sent as the response to host if the target is busy with processing or preparingdata.

The following flow charts demonstrate the communication flow of how the host readsping packet, ACK and response from the target.

Fetch Ping response

Yes

Yes

End

Report Error

No

No

Read 1 bytefrom target

0x5A received?

packet

Read leftover bytesof ping response

0x7A received?


Figure 6-1. Host reads ping response from target via I2C

Fetch ACK

No Yes

End

No

Process NAK Yes

Report an error

No

Yes

No

Reached maximum retries?

Report a timeout error

Yes

0x5A received?

0xA2 received?

0xA1 received?



Figure 6-2. Host reads ACK packet from target via I2C

I2C Peripheral



Fetch Response

Yes

Yespayload length

part from target (2 bytes)

CRC checksum from target

Payload lengthless than supported

length?

Yes

payload data from target

No

Set payload length to maximum

supported lengthNo

No

Reachedmaximum

Report a timeout

Yes

End

No

(2 bytes)


0x5A received?

0xA4received?


retries?

error (End)

Read Read

Read

Figure 6-3. Host reads response from target via I2C

6.3 SPI PeripheralThe Kinetis bootloader supports loading data into flash via the SPI peripheral, where theSPI peripheral serves as a SPI slave.

Maximum supported baud rate of SPI depends on the clock configuration fields in theBootloader Configuration Area (BCA). The typical supported baud rate is 400 kbps withthe factory settings. The actual baud rate is lower or higher than 400 kbps, depending onthe actual value of the clockFlags and clockDivider fields in the BCA.

The Kinetis Flashloader supports 400 kbps as the SPI baud rate.

Because the SPI peripheral serves as a SPI slave device, each transfer should be startedby the host, and each outgoing packet should be fetched by the host.

The transfer on SPI is slightly different from I2C:• Host receives 1 byte after it sends out any byte.• Received bytes should be ignored when host is sending out bytes to target• Host starts reading bytes by sending 0x00s to target• The byte 0x00 is sent as response to host if target is under the following conditions:

• Processing incoming packet• Preparing outgoing data• Received invalid data

Chapter 6 Supported peripherals



The following flowcharts demonstrate how the host reads a ping response, an ACK and acommand response from target via SPI.

Fetch Ping response

Yes

Yes

End

Report Error

No

No0x5A received?

0xA7 received?

Send 0x00 to shift out 1 bytefrom target


Send 0x00s to shift out leftover bytesof ping response

Figure 6-4. Host reads ping packet from target via SPI

Fetch ACK

No

Yes

No

Next action

No

Process NAK Yes

Report an error

No

Yes

No

maximum


Yes

0x5Areceived?

0xA2received?

0xA1received?



Reached

retries?

Figure 6-5. Host reads ACK from target via SPI

SPI Peripheral



Fetch Response

Yes

Yes out payload length part from target

(2 bytes)

out CRC checksum from target


length?

Yes

out payload data from target

No


supported lengthNo

No

maximum

Report a timeout error (End)

Yes

End

No(2 bytes)

0x5Areceived?

0xA4received?

Reached

retries?



Write 0x00s to shift Write 0x00s to shift

Write 0x00s to shift

Figure 6-6. Host reads response from target via SPI

6.4 UART PeripheralThe Kinetis bootloader integrates an autobaud detection algorithm for the LPUARTperipheral, thereby providing flexible baud rate choices.

Autobaud feature: If LPUARTn is used to connect to the bootloader, then theLPUARTn_RX (PTB2)(PTA1) pin must be kept high and not left floating during thedetection phase in order to comply with the autobaud detection algorithm. After thebootloader detects the ping packet (0x5A 0xA6) on LPUARTn_RX, the bootloaderfirmware executes the autobaud sequence. If the baudrate is successfully detected, thenthe bootloader sends a ping packet response [(0x5A 0xA7), protocol version (4 bytes),protocol version options (2 bytes) and crc16 (2 bytes)] at the detected baudrate. TheKinetis bootloader then enters a loop, waiting for bootloader commands via the LPUARTperipheral.

NOTEThe data bytes of the ping packet must be sent continuously(with no more than 80 ms between bytes) in a fixed LPUARTtransmission mode (8-bit data, no parity bit and 1 stop bit). Ifthe bytes of the ping packet are sent one-by-one with more than80 ms delay between them, then the autobaud detection




algorithm may calculate an incorrect baud rate. In this case, theautobaud detection state machine should be reset.

Supported baud rates: The baud rate is closely related to the MCU core and systemclock frequencies. Typical baud rates supported are 9600, 19200, 38400, and 57600. Ofcourse, to influence the performance of autobaud detection, the clock configuration inBCA can be changed.

Packet transfer: After autobaud detection succeeds, bootloader communications cantake place over the LPUART peripheral. The following flow charts show:

• How the host detects an ACK from the target• How the host detects a ping response from the target• How the host detects a command response from the target

Waitfor ACK

No Yes

End

No

Process NAK Yes

Report an error

No

Yes

No

Reachedmaximum


Yes

0x5A received?

0xA2received?

0xA1 received?

Wait for 1 bytefrom target


retries?

Figure 6-7. Host reads an ACK from target via LPUART

UART Peripheral



Wait forping response

Yes

Yes

End

Report Error

No

No



0x5A received?

0xA7 received?

Wait forremaining bytesof ping responsepacket

Figure 6-8. Host reads a ping response from target via LPUART

Waitfor response

Yes

YesWait for payload length part from target (2 bytes)

Wait for CRC checksum from


length?

Yes

Wait for payload data from target

No


supported lengthNo

No

Reachedmaximum

Report a timeout error (End)

Yes

End

No

0x5A received?

0xA4received?



retries?

target (2 bytes)

Figure 6-9. Host reads a command response from target via LPUART

6.5 USB PeripheralThe Kinetis bootloader supports loading data into flash via the USB peripheral. Thetarget is implemented as a USB HID class.

USB HID does not use framing packets; instead the packetization inherent in the USBprotocol itself is used. The ability for the device to NAK Out transfers (until they can bereceived) provides the required flow control; the built-in CRC of each USB packetprovides the required error detection.




6.5.1 Clock configuration

The bootloader supports the crystal-less USB feature. If the USB peripheral is enabled,the bootloader enables the 48-MHz IRCHIRC (by setting SIM_SOPT2[USBSRC |PLLFSLSEL] to 1). The flashloaderROM also enables the USB clock recovery feature(by setting USB_CLK_RECOVER_CTRL[CLOCK_RECOVER_EN] to 1 andUSB_CLK_RECOVER_IRC_EN[IRC_EN] to 1).

6.5.2 Device descriptor

The Kinetis bootloader configures the default USB VID/PID/Strings as below:

Default VID/PID:

• VID = 0x15A2• PID = 0x0073

Default Strings:

• Manufacturer [1] = "Freescale Semiconductor Inc."• Product [2] = "Kinetis bootloader"

You can customize the USB VID/PID/Strings with the Bootloader Configuration Area(BCA) of the flash. For example, the USB VID and PID can be customized by writing thenew VID to the usbVid(BCA + 0x14) field and the new PID to the usbPid(BCA + 0x16)field of the BCA in flash. To change the USB strings, you need to prepare a structure(like the one shown below) in the flash, and then write the address of the g_languagesstructure to the usbStringsPointer(BCA + 0x18) field of the BCA.

g_languages = { USB_STR_0, sizeof(USB_STR_0), (uint_16)0x0409, (const uint_8 **)g_string_descriptors, g_string_desc_size}; the USB_STR_0, g_string_descriptors and g_string_desc_size are defined as below. USB_STR_0[4] = {0x02, 0x03, 0x09, 0x04 }; g_string_descriptors[4] = { USB_STR_0, USB_STR_1, USB_STR_2, USB_STR_3}; g_string_desc_size[4] = { sizeof(USB_STR_0), sizeof(USB_STR_1), sizeof(USB_STR_2),

USB Peripheral



sizeof(USB_STR_3)};

You can make your own structure of USB_STR_1, USB_STR_2, USB_STR_3:• USB_STR_1 is used for the manufacturer string.• USB_STR_2 is used for the product string.• USB_STR_3 is used for the serial number string.

By default, the 3 strings are defined as below:

USB_STR_1[] = { sizeof(USB_STR_1), USB_STRING_DESCRIPTOR, 'F',0, 'r',0, 'e',0, 'e',0, 's',0, 'c',0, 'a',0, 'l',0, 'e',0, ' ',0, 'S',0, 'e',0, 'm',0, 'i',0, 'c',0, 'o',0, 'n',0, 'd',0, 'u',0, 'c',0, 't',0, 'o',0, 'r',0, ' ',0, 'I',0, 'n',0, 'c',0, '.',0 }; USB_STR_2[] = { sizeof(USB_STR_2), USB_STRING_DESCRIPTOR, 'M',0, 'K',0, ' ',0, 'M',0, 'a',0, 's',0, 's',0, ' ',0, 'S',0, 't',0, 'o',0, 'r',0, 'a',0, 'g',0, 'e',0 }; USB_STR_3[] = { sizeof(USB_STR_3),




USB_STRING_DESCRIPTOR, '0',0, '1',0, '2',0, '3',0, '4',0, '5',0, '6',0, '7',0, '8',0, '9',0, 'A',0, 'B',0, 'C',0, 'D',0, 'E',0, 'F',0 };

6.5.3 Endpoints

The HID peripheral uses 3 endpoints:

• Control (0)• Interrupt IN (1)• Interrupt OUT (2)

The Interrupt OUT endpoint is optional for HID class devices, but the Kinetis bootloaderuses it as a pipe, where the firmware can NAK send requests from the USB host.

6.5.4 HID reports

There are 4 HID reports defined and used by the bootloader USB HID peripheral. Thereport ID determines the direction and type of packet sent in the report; otherwise, thecontents of all reports are the same.

Report ID Packet Type Direction

1 Command OUT

2 Data OUT

3 Command IN

4 Data IN

For all reports, these properties apply:

Usage Min 1


USB Peripheral



Usage Max 1

Logical Min 0

Logical Max 255

Report Size 8

Report Count 34

Each report has a maximum size of 34 bytes. This is derived from the minimumbootloader packet size of 32 bytes, plus a 2-byte report header that indicates the length (inbytes) of the packet sent in the report.

NOTEIn the future, the maximum report size may be increased, tosupport transfers of larger packets. Alternatively, additionalreports may be added with larger maximum sizes.

The actual data sent in all of the reports looks like:

0 Report ID

1 Packet Length LSB

2 Packet Length MSB

3 Packet[0]

4 Packet[1]

5 Packet[2]

...

N+3-1 Packet[N-1]

This data includes the Report ID, which is required if more than one report is defined inthe HID report descriptor. The actual data sent and received has a maximum length of 35bytes. The Packet Length header is written in little-endian format, and it is set to the size(in bytes) of the packet sent in the report. This size does not include the Report ID or thePacket Length header itself. During a data phase, a packet size of 0 indicates a data phaseabort request from the receiver.




USB Peripheral



Chapter 7Peripheral interfaces

7.1 Introduction

The block diagram shows connections between components in teh architecture of theperipheral interface.

Figure 7-1. Components peripheral interface

In this diagram, the byte and packet interfaces are shown to inherit from the controlinterface.

All peripheral drivers implement an abstract interface built on top of the driver's internalinterface. The outermost abstract interface is a packet-level interface. It returns thepayload of packets to the caller. Drivers which use framing packets have another abstractinterface layer that operates at the byte level. The abstract interfaces allow the higherlayers to use exactly the same code regardless which peripheral is being used.



The abstract packet interface feeds into the command and data packet processor. Thiscomponent interprets the packets returned by the lower layer as command or datapackets.

7.2 Abstract control interface

This control interface provides a common method to initialize and shutdown peripheraldrivers. It also provides the means to perform the active peripheral detection. No datatransfer functionality is provided by this interface. That is handled by the interfaces thatinherit the control interface.

The main reason this interface is separated out from the byte and packet interfaces is toshow the commonality between the two. It also allows the driver to provide a singlecontrol interface structure definition that can be easily shared.

struct BoatloaderInitInfo{ void * contextArea; //!< Pointer to memory region for use by the driver. uint32_t available; //!< Size of the memory region the driver can use. uint32_t used; //!< Actual number of bytes used by the driver (filled in by the driver).};

struct PeripheralDescriptor { //! @brief Bit mask identifying the peripheral type. //! //! See #_peripheral_types for a list of valid bits. uint32_t typeMask;

//! @brief The instance number of the peripheral. uint32_t instance;

//! @brief Control interface for the peripheral. const peripheral_control_interface_t * controlInterface;

//! @brief Byte-level interface for the peripheral. //! //! May be NULL since not all periperhals support this interface. const peripheral_byte_inteface_t * byteInterface;

//! @brief Packet level interface for the peripheral. const peripheral_packet_interface_t * packetInterface;};

struct PeripheralControlInterface{ status_t (*minimalInit)(const PeripheralDescriptor * self, BoatloaderInitInfo * info); void (*minimalShutdown)(const PeripheralDescriptor * self); bool (*pollForActivity)(const PeripheralDescriptor * self);

Abstract control interface



status_t (*init)(const PeripheralDescriptor * self, BoatloaderInitInfo * info); void (*shutdown)(const PeripheralDescriptor * self);

Table 7-1. Abstract control interface

Interface Description

minimalInit() Initialize the driver only enough to detect start ofcommunications.

minimalShutdown() Shutdown the driver from its minimal init state.

pollForActivity() Check whether communications has started.

init() Fully initialize the driver.

shutdown() Shutdown the fully initialized driver.

After minimalShutdown() is called, the driver is expected to no longer use any memorythat it allocated through the BootloaderInitInfo structure.

7.3 Abstract byte interface

This interface exists to give the framing packetizer, which is explained in the latersection, a common interface for the peripherals that use framing packets.

The abstract byte interface inherits the abstract control interface.

struct PeripheralByteInterface{ status_t (*init)(const peripheral_descriptor_t * self, bootloader_init_info_t * info); status_t (*read)(uint8_t * buffer, uint32_t requestedBytes, uint32_t * actualBytes); status_t (*write)(const uint8_t * buffer, uint32_t byteCount);};

Table 7-2. Abstract byte interface


init() Initialize the interface.

read() Return the requested number of bytes. Blocks until all bytesavailable.

write() Write the requested number of bytes.

The read() interface returns a pointer into the driver's internal buffer. No data is copied.The driver must ensure that the returned range of bytes is not overwritten until the nextcall into read(). Each call of this interface tells the driver that it may reuse the range ofbytes that it last returned.

Chapter 7 Peripheral interfaces



7.4 Abstract packet interface

The abstract packet interface inherits the abstract control interface.

struct PeripheralPacketInterface{ status_t (*init)(const PeripheralDescriptor * self, BoatloaderInitInfo * info); status_t (*readPacket)(const PeripheralDescriptor * self, uint8_t ** packet, uint32_t * packetLength, packet_type_t packetType); status_t (*writePacket)(const PeripheralDescriptor * self, const uint8_t * packet, uint32_t byteCount, packet_type_t packetType); void (*abortDataPhase)(const PeripheralDescriptor * self); status_t (*finalize)(const PeripheralDescriptor * self); uint32_t (*getCurrentMaxBufferSize)(const PeripheralDescriptor * self); status_t (*requestNewMaxBufferSize)(const PeripheralDescriptor * self, uint32_t newBufferSize);};

Table 7-3. Abstract packet interface


init() Initialize the peripheral.

readPacket() Read a full packet from the peripheral.

writePacket() Send a complete packet out the peripheral.

abortDataPhase() Abort receiving of data packets.

finalize() Shut down the peripheral when done with use.

getCurrentMaxBufferSize() Returns the current maximum buffer size.

requestNewMaxBufferSize() Requests to set a new maximum buffer size.

7.5 Framing packetizer

The framing packetizer processes framing packets received via the byte interface withwhich it talks. It builds and validates a framing packet as it reads bytes. And it constructsoutgoing framing packets as needed to add flow control information and command ordata packets. The framing packet also supports data phase abort.

7.6 USB HID packetizer

Abstract packet interface



The USB HID packetizer implements the abstract packet interface for USB HID, takingadvantage of the USB's inherent flow control and error detection capabilities. The USBHID packetizer provides a link layer that supports variable length packets and data phaseabort.

7.7 Command/data processor

This component reads complete packets from the abstract packet interface, and interpretsthem as either command packets or data packets. The actual handling of each commandis done by command handlers called by the command processor. The command handlertells the command processor whether a data phase is expected and how much data it isexpected to receive.

If the command/data processor receives a unexpected command or data packet, it ignoresit. In this case, the communications link resynchronizes upon reception of the next validcommand.

Chapter 7 Peripheral interfaces



Command/data processor



Chapter 8Memory interface

8.1 Abstract interface

The bootloader uses a common, abstract interface to implement the memory read/write/fill commands. This is to keep the command layer from having to know the details of thememory map and special routines.

This shared memory interface structure is used for both the high-level abstract interface,as well as low-level entries in the memory map.

struct MemoryInterface{ status_t (*read)(uint32_t address, uint32_t length, uint8_t * buffer); status_t (*write)(uint32_t address, uint32_t length, const uint8_t * buffer); status_t (*fill)(uint32_t address, uint32_t length, uint32_t pattern);}

The global bootloader context contains a pointer to the high-level abstract memoryinterface, which is one of the MemoryInterface structures. The internal implementation ofthis abstract interface uses a memory map table, referenced from the global bootloadercontext that describes the various regions of memory that are accessible and providesregion-specific operations.

The high-level functions are implemented to iterate over the memory map entries until itfinds the entry for the specified address range. Read and write operations are notpermitted to cross region boundaries, and an error is returned if such an attempt is made.

The BootloaderContext::memoryMap member is set to an array of these structures:

struct MemoryMapEntry{ uint32_t startAddress; uint32_t endAddress; const MemoryInterface * interface;};

This array must be terminated with an entry with all fields set to zero.



The same MemoryInterface structure is also used to hold the memory-type-specificoperations.

Note that the MemoryMapEntry::endAddress field must be set to the address of the lastbyte of the region, because a <= comparison is used.

During bootloader startup, the memory map is copied into RAM and modified to matchthe actual sizes of flash and RAM on the chip.

8.2 Flash driver interface

The flash driver uses the common memory interface to simplify the interaction with flash.It takes care of high level features such as read back verification, flash protectionawareness, and so on. The flash memory functions map to the interface functions as so:

const memory_region_interface_t g_flashMemoryInterface = { .read = &normal_mem_read, .write = &flash_mem_write, .fill = &flash_mem_fill};

Bootloader startup code is responsible for initializing the flash memory.

API Description

normal_mem_read() Performs a normal memory read.

flash_mem_write() Calls the low-level flash_program() API. Also performsprogram verification if enabled with the Set Propertycommand.

flash_mem_fill() Performs intelligent fill operations on flash memory ranges. Ifthe fill patterns are all 1's, special action is taken. If the rangeis a whole number of sectors, then those sectors are erasedrather than filled. Any part of an all-1's fill that is not sector-aligned and -sized is ignored (the assumption being that it hasbeen erased to 1's already). Fills for patterns other than all 1'scall into flash_program().

Both flash_mem_write() and flash_mem_fill() checks the flash protection status for thesectors being programmed or erased and return an appropriate error if the operation is notallowed.

8.3 Low level flash driver

Flash driver interface



The low level flash driver (LLFD) handles erase and write operations on a word basis. Itcannot perform writes of less than a full word.

Bootloader startup code is responsible for initializing and shutting down the LLFD.

status_t flash_init();status_t flash_erase_all();status_t flash_erase(uint32_t start, uint32_t lengthInBytes);status_t flash_program(uint32_t start, uint32_t * src, uint32_t lengthInBytes);status_t flash_get_security_state(flash_security_state_t * state);status_t flash_security_bypass(const uint8_t * backdoorKey);status_t flash_verify_erase_all(flash_margin_value_t * margin);status_t flash_verify_erase(uint32_t start, uint32_t lengthInBytes, flash_margin_value_t margin);status_t flash_verify_program(uint32_t start, uint32_t lengthInBytes, const uint8_t * expectedData, flash_margin_value_t margin, uint32_t failedAddress, uint8_t *failedData);status_t flash_is_region_protected(uint32_t start, uint32_t lengthInBytes, flash_protection_state_t * protection_state)status_t flash_get_property(flash_property_t whichProperty, uint32_t * value)

Chapter 8 Memory interface



Low level flash driver



Chapter 9Kinetis bootloader porting

9.1 Introduction

This chapter discusses the steps required to port the Kinetis bootloader to an unsupportedKinetis MCU. Freescale is working to bring bootloader support to the entire Kinetisportfolio, but some devices still require user porting until all legacy device ports arecomplete. Each step of the porting process is discussed in detail in the following sections.

9.2 Choosing a starting point

The first step is to download the latest bootloader release. Freescale releases updates forthe bootloader multiple times per year, so having the latest package is important forfinding the best starting point for your port. To find the most recent bootloader release,freescale.com/KBOOT .

The easiest way to port the bootloader is to choose a supported target that is the closestmatch to the desired target MCU.

NOTEJust because a supported device has a similar part number to thedesired target MCU, it may not necessarily be the best startingpoint. To determine the best match, reference the datasheet andreference manual for all of the supported Kinetis devices.

9.3 Preliminary porting tasks



http://www.freescale.com/KBOOT

All references to paths in the rest of this chapter are relative to the root of the extractedKinetis bootloader package. The container folder is namedFSL_Kinetis_Bootloader_<version>. Before jumping in and modifying source code, thefollowing tasks should be performed.

9.3.1 Download device header files

The most manual process in porting the bootloader to a new target is editing the deviceheader files. This process is very time consuming and error prone, so Freescale providesCMSIS-compatible packages for all Kinetis devices that contain bootloader-compatibledevice header files. These packages can be found on the product page for the MCU.

NOTEIt is not recommended to proceed with a port if a package doesnot yet exist for the desired target MCU.

In the downloaded package, locate the folder with the header files. The folder is namedafter the MCU (for example, “MK64F12”) and contains a unique header file for eachperipheral in addition to regs.h and system_<device>.h files. Copy the entire folder intothe /src/include/device folder of the bootloader tree.

9.3.2 Copy the closest match

Copy the folder of the MCU that most closely matches the target MCU in the /targetsfolder of the bootloader source tree. Rename it to coincide with the target MCU partnumber.

Once the files are copied, browse the newly created folder. Rename all files that havereference to the device from which they were copied. The following files need to berenamed:

• clock_config_<old_device>.c —> clock_config_<new_device>.c• hardware_init_<old_device>.c —> hardware_init _<new_device>.c• memory_map_<old_device>.c —> memory_map _<new_device>.c• peripherals_<old_device>.c —> peripherals _<new_device>.c• startup_<old_device>.c —> startup _<new_device>.c

9.3.3 Provide device startup file (vector table)

Preliminary porting tasks



A device-specific startup file is a key piece to the port. The bootloader may not functioncorrectly without the correct vector table. A startup file from the closest match MCU canbe used as a template, but it is strongly recommended that the file be thoroughly checkedbefore using it in the port due to differences in interrupt vector mappings between Kinetisdevices.

The startup file should be created and placed into a folder that references the target MCUand toolchain in the /src/startup folder of the bootloader source tree. Startup files arealways assembly (*.s) and are named startup_<device>.s.

9.3.4 Clean up the IAR project

The folder copy performed in step 1.2.2 copies more than just source code files. Inside ofthe newly created /targets/<device> folder, locate the IAR workspace file(bootloader.eww) and open it. This image shows an example of what a workspace lookslike and the files that need to be touched.

Figure 9-1. IAR workspace

Once changes have been made, update the project to reference the target MCU. This canbe found in the project options.

Chapter 9 Kinetis bootloader porting



Figure 9-2. Project options

9.3.5 Bootloader peripherals

There is a C/C++ preprocessor define that is used by the bootloader source to configurethe bootloader based on the target MCU. This define must be updated to reference thecorrect set of device-specific header files.

Preliminary porting tasks



Figure 9-3. Options for node "freedom_bootloader"

The linker file needs to be replaced if the memory configuration of the target MCUdiffers from the closest match. This is done in the linker settings, which is also part of theproject options.




Figure 9-4. Porting guide change linker file

9.4 Primary porting tasks

Actual porting work can begin when the basic file structure and source files are in place.This section describes which files need to be modified and how to modify them.

9.4.1 Header file modification

In section 1.2.1, the Freescale-provided CMSIS header files were downloaded and copiedto the bootloader tree. For these header files to be used by the bootloader, thefsl_device_registers.h file in /src/include/device/src needs to be modified.

Primary porting tasks



The file is organized by MCU family and points the bootloader to the device-specificheader files. A new #elif case needs to be added to the bottom of the list (before the #elsethat indicates error) that references the target MCU. Note the define used to identify thetarget MCU must match the define added in section 1.2.5, in Figure 3. With the newsection in place, reference the content used for other devices to determine what needs tobe added to the new section.

9.4.2 Bootloader peripherals

There are two steps required to enable and configure the desired peripherals on the targetMCU:

• Choosing which peripherals can be used by the bootloader.• Configuring the hardware at a low level to enable access to those peripherals.

9.4.2.1 Supported peripherals

The bootloader uses the peripherals_<device>.c file to define which peripheral interfacesare active in the bootloader. The source file itself includes a single table, g_peripherals[],that contains active peripheral information and pointers to configuration structures. Thisfile is found in /targets/<device>/src.

It’s important to only place configurations for peripherals that are present on the targetMCU. Otherwise, the processor generates fault conditions when trying to initialize aperipheral that is not physically present.

In terms of the content of each entry in the g_peripherals[] table, it is recommended toreuse existing entries and only modify the .instance member. For example, starting withthe following UART0 member, it can be changed to UART1 by simplychanging .instance from “0” to “1”.

{ .typeMask = kPeripheralType_UART, .instance = 0, .pinmuxConfig = uart_pinmux_config, .controlInterface = &g_scuartControlInterface; .byteInterface = &g_scuartByteInterfacek; .packetInterface = &g_framingPacketInterface; }

When the table has all required entries, it must be terminated with a null { 0 } entry.

9.4.2.2 Peripheral initialization




Once the desired peripheral configuration has been selected, the low level initializationmust be accounted for. The bootloader automatically enables the clock and configures theperipheral, so the only thing required for the port is to tell the bootloader which pins touse for each peripheral. This is handled in the hardware_init_<device>.c file in /targets/<device>/src. The hardware_init_<device>.c file also selects the boot pin used by thebootloader, which may need to be changed for the new target MCU.

This file most likely requires significant changes to account for the differences betweendevices when it comes to pin routing. Each function should be checked for correctnessand modified as needed.

9.4.2.3 Clock initialization

The Kinetis bootloader typically uses the MCU’s default clock configuration. This isdone to avoid dependencies on external components and simplify use. In some situations,the default clock configuration cannot be used due to accuracy requirements of supportedperipherals. On devices that have on-chip USB, the default system configuration is notsufficient and the bootloader configures the device to run from the high-precision internalreference clock (IRC48).

The bootloader uses the clock_config_<device>.c file in /targets/<device> to override thedefault clock behavior. If the target MCU of the port supports USB, this file can be used.If not, the functions within clock_config_<device>.c can be stubbed out or set towhatever the port requires.

9.4.3 Bootloader configuration

The bootloader must be configured in terms of the features it supports and the specificmemory map for the target device. Features can be turned on or off by using #definestatements in the bootloader_config.h file in /targets/<device>/src. The supported featurescan be seen in command.c (g_commandHandlerTable[] table) in the /src/bootloader/srcfolder. All checks that reference a BL_* feature can be turned on or off. Examples ofthese features are BL_MIN_PROFILE, BL_HAS_MASS_ERASE andBL_FEATURE_READ_MEMORY.

One of the most important bootloader configuration choices is where to set the startaddress (vector table) of the user application. This is determined by theBL_APP_VECTOR_TABLE_ADDRESS define in bootloader_config.h. Most




bootloader configurations choose to place the user application at address 0xA000 sincethat accommodates the full featured bootloader image. It’s possible to move this startaddress if the resulting port reduces features (and thus, code size) of the bootloader.

9.4.4 Bootloader memory map configuration

The MCU device memory map and flash configuration must be defined for properoperation of the bootloader. The device memory map is defined in the g_memoryMap[]structure of the memory_map_<device>.c file, which can be found in /targets/<device>/src. An example memory map configuration is shown.

memory_map_entry_t g_memoryMap[] = { // Flash array (1024KB) { 0x00000000, 0x000fffff, &g_flashMemoryInterface }, // SRAM (256KB) { 0x1fff0000, 0x2002ffff, &g_normalMemoryInterface }, // AIPS peripherals { 0x40000000, 0x4007ffff, &g_deviceMemoryInterface }, // GPIO { 0x400ff000, 0x400fffff, &g_deviceMemoryInterface }, // M4 private peripherals { 0xe0000000, 0xe00fffff, &g_deviceMemoryInterface }, // Terminator { 0 } };

In addition to the device memory map, the bootloader needs information about thespecific flash configuration of the target MCU. This includes things such as sector size,features, and FlexRAM.

The fsl_flash_features.h file needs to be modified to provide the bootloader with thisinformation. This file is located in /src/drivers/flash/src. To determine which features theflash on the target MCU supports, utilize the device’s reference manual. Many Kinetisdevices share similar flash configurations so it may be possible to use an existing flashconfiguration for the port’s target MCU. Use the same CPU define referenced in sections1.2.5 and 1.3.1 to enable a flash configuration.

The correct flash density and SRAM initialization files must be selected according to thetarget device. Both of these files are split based on Cortex-M4 and Cortex-M0+ baseddevices, so the likelihood of having to change them is low. However, if required, the fileshighlighted in this figure can be replaced with their alternatives.

The flash_densities_k_series.c file is located in /src/drivers/flash/src and it’s alternative isflash_densities_kl_series.c, which corresponds to devices with a Cortex-M0+ core.

The sram_init_cm4.c file is located in /src/memory/src and it’s alternative issram_init_cm0plus.c.




Figure 9-5. Memory map configuration




Chapter 10Creating a custom flash-resident bootloader

10.1 Introduction

In some situations the ROM-based or full-featured flash-resident bootloader cannot meetthe requirements of a use application. Examples of such situations include specialsignaling requirements on IO, peripherals not supported by the bootloader, or the morebasic need to have as small of a code footprint as possible (in the case of the flash-resident bootloader). This section discusses how to customize the flash-residentbootloader for a specific use case.

10.2 Where to start

The Kinetis bootloader package comes with various preconfigured projects, includingconfigurations for a flashloader (if applicable for the device) and a flash-residentbootloader. These projects enable all supported features by default, but can easily bemodified to suit the needs of a custom application.

The IAR workspace containing these preconfigured options is located in the<install_dir>/targets/<mcu> folder, where <install_dir> is the folder name of the Kinetisbootloader package once extracted (typically FSL_Kinetis_Bootloader_<version>) and<mcu> is the family of the MCU target. Inside of this folder there is a bootloader.ewwfile, which is the IAR workspace. The example shows the projects available in theworkspace for the K22F512 MCU family. There are configurations for both TWR andFRDM platforms, assuming the boards exist for the specific MCU family.



Figure 10-1. Projects available in workspace

Each of the projects in the workspace is configured to support all features of thebootloader. This means every peripheral interface that the MCU supports is enabled. Thismakes the bootloader very rich in features, but it also has the largest code footprint,which can be considerable on MCUs with smaller flash configurations.

10.3 Flash-resident bootloader source tree

It is important to understand the source tree to understand where modifications arepossible. Here is an example of a source treee for one of the bootloader configurations.

Flash-resident bootloader source tree



Figure 10-2. Source tree for bootloader configuration

There are two folders in each bootloader project: a MCU-specific folder and a “src”folder. All files in the MCU-specific folder are located in the <install_dir>/targets/<mcu>/src folder, and are very specific to the target MCU. The “src” folder is located atthe top level of the bootloader tree, and the subfolders in the project correspond to thereal folder/file structure on the PC. The files in the “src” folder are the core files of thebootloader, and include everything from peripheral drivers to individual commands.

Chapter 10 Creating a custom flash-resident bootloader



The bootloader source is separated in a way that creates a clear line between what a userneeds to modify and what they do not. Among other things, the files in the MCU-specificfolder allow the application to select which peripherals are active as well as how toconfigure the clock, and are intended to be modified by the user. The files in the “src”folder can be modified, but should only require modification in cases where very specificcustomization is needed in the bootloader.

10.4 Modifying source files

The files that cover the majority of the customization options needed by applications arelocated in the MCU-specific folder. These files allow modification to the basicconfiguration elements of the bootloader application, and are not associated with the corefunctionality of the bootloader.

In the MCU-specific folder, the source files contain this information:

• bootloader_config.h – Bootloader configuration options such as encryption,timeouts, CRC checking, the UART module number and baud rate, and mostimportantly, the vector table offset for the user application.

• clock_config_<mcu>.c – Configures the clock for the MCU. This includes system,bus, etc.

• hardware_init_<mcu>.c – Enables and configures peripherals used by theapplication. This includes pin muxing, peripheral initialization, and the pin used as abootloader re-entry (bootstrap) mechanism.

• memory_map_<mcu>.c – Contains a table that stores the memory map informationfor the targeted MCU.

• peripherals_<mcu>.c – Contains the table used by the bootloader to check whichperipheral interfaces are enabled. This is the file used to disable any unwanted orunused peripheral interfaces.

10.5 Example

One of the most common customizations performed on the Kinetis bootloader isremoving unused or unwanted peripheral interfaces. The default configuration of thebootloader enables multiple interfaces, including UART, SPI, I2C and (on some devices)USB. This example will describe how to modify the provided bootloader projects to useonly the UART interface. The same methodology can be used to select any of thesupported interfaces.

Modifying source files



10.6 Modifying the peripherals_<mcu>.c file

The first step required is modifying the g_peripherals table in the peripherals_<mcu>.cfile, located in <install_dir>/targets/<mcu>/src. The file only contains a table, definingwhich peripheral interfaces are used by the bootloader and their specific configuration,including instance. If only one interface is desired, all entries other than the desiredinterface can be removed.

const peripheral_descriptor_t g_peripherals[] = { // UART1 { .typeMask = kPeripheralType_UART, .instance = 1, .pinmuxConfig = uart_pinmux_config, .controlInterface = &g_scuartControlInterface, .byteInterface = &g_scuartByteInterface, .packetInterface = &g_framingPacketInterface }, { 0 } // Terminator};

The UART instance can be changed here as well. If another UART is desired, simplychange the instance variable. The same applies to other peripheral interfaces.

10.7 Removing unused files from the project

To optimize code size, files related to the unusual peripheral interfaces must be removedfrom the project. The files that should be removed are:

• <peripheral_name>_peripheral_interface.c located under the src/bootloader/srcfolder.

• Folders for unused drivers, under the src/drivers folder.• If the USB is not present, simply remove the “usb_device” folder.

Chapter 10 Creating a custom flash-resident bootloader



Figure 10-3. Removing unused files

With these items complete, simply rebuild the bootloader project. Unused peripheralsources will be excluded from the executable, leaving only the desired interface.

Removing unused files from the project



Chapter 11Revision history

Revision History

Table 11-1. Revision History

Revision number Date Substantive changes

Rev. 0 12/2014 Initial release





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